Fastener inserting tools



Nov. 10, 1959 W. P. CROSSEN FASTENER INSERTING TOOLS 2 Sheets-Sheet 1 Filed Dec. 17, 1956 m w W r m m m6 w c w 3 HP& 9 m .m W m h M QW I M M WW O Q kw Qw g 9% Q3 t -w. l g F n3 Q3 9Q 8Q W m3 w\\\ & ww

Nov. 10, 1959 w. P. CROSSEN 2,911,645

FASTENER INSERTING TOOLS By his Attorney l 2,91 1,645 Ice "Patented Nov. 1 5 .1959

FASTENER IN SERTIN G TOOLS William P. Crossen, Ipswich, Mass., assignor to United Shoe Machinery Corporation, Flemington, N.J., a corporation of New Jersey Application December 17, 1956, Serial No. 628,797 6 Claims. (Cl. 144.4) I

This invention relates to fastener inserting and particularly to portable tools of the percussive type which are adapted for the impact driving of fasteners such as, nails, sash pins, etc. This type of tool is frequently fed from a remotely located fastener orienting and feeding mechanism similar to that disclosed in United States Letters Patent No. 2,785,400, granted March 19, 1957 in the names of Donald B. Mcllvin et al., wherein a fastener is propelled by a blast of air through a flexible conduit to the inserting tool upon receipt of a signal from the tool. In order to propel nails of the larger sizes, i.e. 16d and upward, through a delivery conduit which may be 'as long as 25 or 30 ft., air under substantial pressure is used and by the time the nail reaches the inserting tool it usually has attained considerable momentum. The nail is generally received in the tool by mechanism in the form of yieldable supporting jaws for positioning it in the path of a driver. However, it is not uncommon for the nail to enter the jaws with such speed and momentum that it passes completely out of the jaws which, of course. results in the tool misfiring.

An additional problem has been encountered in driving successfully into hard wood, box nails oflarge sizes having relatively thin shanks in proportion to their lengths. This is because such nails are prone to bending unless they are securely supported in a direction transversely of the direction of applied force along their axes. Attempts have been made to'remedy these situations by employing heavy jaws which are cantilever mounted and constructed of stilf spring steel. Another approach involves providing pivotally mounted jaws of rigid material with separate force applying means to create nail supporting force. Applicant has further found that to support nails successfully against bending in a range of sizes, the 'jaw force required necessarily varies depending upon the length and size of the nail.

It is essential in driving a nail flush with the surface of the work that the driver pass into if not completely through the jaws, the driver and/orthe head of the nail causing the jaws to yield outwardly. When suflicient force is applied by the jaws to support a nail adequately. it has been found that the driver is often gripped within the jaws upon completion of the driving stroke and must be manually withdrawn before the next nail can be driven, resulting in a loss of time. a

It is, therefore, an object of this inventionto provide an inserting tool having jaws of suflicient strength to receive and hold a nail propelled theretowith substantial momentum and to support the nail against bending, which jaws are yieldable to admit the entry ofthe nail driver and automatic means to retract the driver from the jaws upon the completion of the nail driving stroke.

In accordance with the features of this invention there is provided a fastener inserting tool having a driver and a fluid motor of well-known construction for imparting driving motion thereto. A fastener retainingnosepiece and a pair of jaws on the nosepiece support the fastener in the path of motion of the driver. Jaw tension is varied by the provision of a plurality of removable annular flexible members surrounding the jaws. "Ihe driver is movable between the jaws to drive a fastener therefrom and means in the form of an air actuated piston is provided to withdraw the driver from within the jaws after the fastener has been driven. Means are also provided to vary the force with which the driver is retracted from the jaws. p

The above and other features of the invention including various novel details of construction and combination of parts will now be more particularly described with ref erence to the accompanying drawings and pointed out in the claims.

In the drawings,

Fig. 1 is a side elevation partly in section of a nail driving tool embodying the invention; and

Fig. 2 is a diagrammatical showing of the tool shown in Fig. 1 and its pneumatic operating circuit as employed with a nail orienting and feeding mechanism.

on the tool is movable relative to the fluid motor The invention is herein illustrated as incorporated in a pneumatically operated multiple-blow nail driving gun However, it may be employed with other types of im pact fastener inserting tools as well. The illustrated gun is of conventional commercial design and comprises a pistol grip air hammer 10 and a nail handling nosepiece 12 slidably mounted thereon. A fluid motor 14, hereinafter described in more detail, in the air hammer oper ates to impart a series of short, rapid driving strokes to a nail driver 16 which extends into the nosepiece 12. Compressed air is supplied to the gun through a line 18 and is introduced to the motor 14 by actuating a trigger 20, which, through the action of a bell crank 22 unseats a valve 24 admitting air to a chamber 26 from passageways 28 and 30 communicating with the air line 18. .The compressed air in operating the motor 14 passes. therethrough to atmosphere in a known manner. Pressurization of the chamber 26 not only actuates the motor 14 but in addition pressurizes a chamber 27 communicating with a signal line 32 which may be connected to a pneumatically operated nail delivering device D (Fig. 2) of the type disclosed in the above-mentioned Mcllvin et a1. patent. The nail delivering device forms no part of the present invention. Pressurization of the signal line 32 activates the nail delivering device preparing it to propel a nail through a flexible delivery conduit 34 to the nosepiece 12 by compressed air upon subsequent depressurization of the signal line, all in a known manner.

A sleeve portion 36 forming a portion of the nosepiece 12 is slidable telescopically over a cylindrical extension 38 of the air hammer 10. A set screw 40 in the sleeve 36 engages a slot 42 in the extension 38 to prevent relative rotation of the parts and to limit the extent of their sliding movements. Formed on the upper part of the nosepiece 12 is a boss 44 having a bore 46 into which fits a nail delivering nozzle 48 to which the flexible nail delivery conduit 34 is secured. In the forward end of the nosepiece 12 and in communication with the nail delivering nozzle 48 is a nail receiving chamber 50.

Pivotally mounted by means of pins 52 fitted in. lugs 54 on the nosepiece are the legs 55 of a pair of jaw members 56 constructed of rigid non-flexing material. Formed on the forward end of each of the jaw legs is a clamping jaw 57. The clamping jaws are arranged to contact each other in substantial axial alinement with the driver 16 and a central portion of each of the jaws is relieved so as to form between them a'substantially cylindrical fastener engaging opening 58 when the jaws are in in entering the opening 58 as it is propelled into the nail vide the yielding force as anail head and the driver pass therethrough, the jaws are subjected to a minimum of internal bending stresses.

The interior of the sleeve 36 forms a cylinder 66, and fitted to the nail driver 16 and slidable within the cylinder 66 is a piston 68. Communicating with the interior of the cylinder 66 is a passageway 70 leading to an air inlet fitting 72.

The nail inserting gun operates in the following manner. The jaws 57 are urged firmly together in a direction substantially normal to the path of movement of the driver by the springs 64. The driver normally occupies a position with its nail engaging end or tip 71 adjacent the rearward end of the nail receiving chamber 50, substantially as shown in Fig. 1. A nail, which is propelled from the delivering device D through the flexible delivery conduit 34, in a known manner, enters the opening 58 in the jaws point'first assisted by the camming surfaces 60. Through a simple trial and error process it is determined how many springs 64 are needed to provide adequate support during the driving process and to provide sufiicient frictional force to prevent the nail from passing prematurely out of the jaws. I V

The nosepiece 12 of the gun is then pressed against the work causing the air hammer 10 and the nosepiece 12 to slide telescopically toward each other until the tip 71 of the driver engages the head of the nail. Upon the depression of the trigger the motor 14 imparts a series of short driving strokes to the driver causing the nail to be driven from the jaws into the work. When the nail has been fully driven home the forward end or tip 71 of the driver will have entered the jaws and will be gripped therein by the force of the springs 64. Upon release of the trigger 20, compressed air enters the cylinder 66 through the fitting 72, by means hereinafter to be described, urging the piston 68, the driver 16 and the air hammer 10 toward the right. The compressed; air also acts on the left-hand end 73 of the cylinder 66 urging the nosepiece 12 to the left thereby withdrawing the-driver from the jaws and telescopically moving the nosepiece and air hammer away from each other. Release of the trigger 20, cuts off the flow of pressurized air to the signal line 32 which signals the delivering device D to propel the next nail through the delivery conduit 34' into the jaws.

Referring to Fig. 2, the means for directing air to the cylinder 66 will now be described. The line 18 which supplies air to the inserting tool is connected to a source of pressurized air passing through a line 74 which also supplies compressed air to the nail delivering device D. The signal line 32 leads to an automatic control valve 76, a branch 77 of the signal line 32 also leading to the nail delivering device D. The valve 76 comprises a valve casing 78 having formed therein a plurality of chambers 80, 82 and 84. Slidable within the casing 78 is a piston 86 having a large diameter piston head 88 and a small diameter piston head 90. Separating the large and small piston heads is a necked area 92 and a cylindrical extension 94 of the same diameter as the small diameter :head 90. An air accumulator 96 communicates with the chamber 82 by way of a line 98 and a passageway 100. The chamber 80 is connected by a line 102 to the source of pressurized fluid by way of the line 74. A variable flow valve 104 communicates with the chamber 84 and the fitting 72 on the inserting tool is connected by a line 106 toa passageway 108 also communicating with the chamber 84.

The piston 86 is normally maintained in the position shown in Fig. 2 by pressurized air in the chamber acting on the small diameter head 90, the chamber 84 being at atmospheric pressure. When the signal line 32 leading from the inserting tool becomes pressurized by actuating the trigger 20, compressed air acts against the large diameter head 88 displacing the piston to the left, the small diameter head 90 entering the chamber 80 permitting the compressed air therein to flow past the necked area 92 and into the accumulator 96 by way of the passageway 100 and the line 98. At this time no air can flow from the chamber 80 to the chamber 84 since the cylindrical extension 94 has entered the right-hand end of the chamber 82. Air which normally would be trapped within the chamber 84 when the piston moves from right to left escapes through the variable flow valve 104;

As stated above, the air hammer 10 is of conventional commercial design and includes the fluid motor 14 which imparts a series of short rapid driving strokes to the driver 16. The driver is actuated by repeated blows of a piston slidably mounted in the axial bore 112 of an air motor cylinder 114. The construction of the valve mechanism for controlling fluid pressure to reciprocate the piston 110 is in accordance with previous known devices of the percussive type. In an example of this type of device there are two inlet ports at the righthand end, as viewed in Fig. 1, of the cylinder 114, one designated 116 opening directly into the right-hand end of the bore 112 and the other 118, leading into a passage way 120, the left-hand end of which joins a port 122 communicating with the left-hand end of the bore 112. On the opposite side of the bore 112 from the port 122 is a port 124 leading by way of a passageway 126 to an exhaust port 127 leading to the exterior of the cylinder 114 to exhaust the air from the left end of the bore 112 during the driving stroke of the piston 110. Surrounding the right-hand end of the cylinder 114 is a floating annular valve 128 which operates alternately to open one inlet port 116 and close the other port 118, and vice versa, in a manner common to percussively driven devices of the prior art.

As stated above, upon the depression of the trigger 20 compressed air is supplied to the gun from the line 18 which pressurizes the chambers 26 and 27. Flow of air into chamber 26 shifts the floating annular valve 128, as viewed in Fig. 1, to open the port 116 and close the port 118 so that pressurized air will be admitted through the port 116 to the right-hand end of the bore 112 for driving the piston to the left. During the driving motion of the piston 110, air is exhausted from the lefthand end portion of the bore 112 through the port 124 and escapes to atmosphere through the exhaust port 127. When the piston 110 closes port 124, annular valve member 128 is shifted by a back pressure impulse through passageway 120 developed by continued movement of piston 110 to close the port 116 and open the port 118 on the opposite side of the cylinder 114. Suflicient pressurized air flows through the passageway 120 to the left-hand end of the bore 112 through the port 122 for driving the piston to the right until it creates suflicient pressure in cylinder 114 to shift the valve 128 into position to open port 116. 1

When the signalline 32 becomes depressurized upon release of the trigger 20, the residual compressed air therein is exhausted into cylinder 114 or to atmosphere through the port 118, passageway 120, port 122, bore 112, port 124, passageway 126 and exhaust port 127, whereu on the piston 86 is again returned to its righthand position by the compressed air within the chamber 80 acting on the left-hand face of the small diameter head 90. Theair within the accumulator 96 then flows through the 5% 98, the passageway 100, the chamber 82, past the necked area 92 of the piston 86, into the chamber 84 and thence through the line 106 into the inserting tool to withdraw the driver from the jaws and to return the nosepiece 12 and the air hammer to their original positions. Some of the air which enters the chamber 84 is free to flow out of the valve 104; however, this valve, being adjustable, controls the amount of air from the accumulator which flows through the line 106 to the tool depending upon the amount of force needed to withdraw the driver from the jaws.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a fastener inserting tool, a driver, motor means operatively connected to said driver for imparting driving motion thereto, a fastener retaining nosepiece movable relative to said motor means, a cylinder fixed to said nosepiece, a pair of yieldable jaws on said nosepiece for supporting a fastener in the path of motion of said driver, said driver extending from said motor means through said cylinder and movable between said jaws to drive the fastener therefrom when said motor means and said nosepiece are moved toward each other, a piston on said driver and slidable within said cylinder, and means to admit pressurized fluid to said cylinder to withdraw the driver from the jaws and to move said nosepiece and said motor means away from each other after the fastener has been driven.

2. In a fastener inserting tool, a driver, motor means operatively connected to said driver for imparting driving motion thereto, a fastener retaining nosepiece movable relative to said motor means, a cylinder fixed to said nosepiece, a pair of yieldable jaws on said nosepiece for supporting a fastener in the path of motion of said driver, said driver extending from said motor means through said cylinder and movable between said jaws to drive the fastener therefrom when said motor means and said nosepiece are moved toward each other, a piston on said driver and slidable within said cylinder, and a control valve operable in timed sequence with said motor means to admit pressurized fluid to said cylinder to withdraw the driver from the jaws and move said nosepiece and said motor means away from each other after the fastener has been driven.

3. In a fastener inserting tool, a driver, motor means operatively connected to said driver for imparting driving motion thereto, a fastener retaining nosepiece movable relative to said motor means, a cylinder fixed to said nosepiece, a pair of yieldable jaws on said nosepiece for supporting a fastener in the path of motion of said driver, said driver extending from said motor means through said cylinder and movable between said jaws to drive the fastener therefrom when said motor means and said nosepiece are moved toward each other, a piston on said driver and slidable within said cylinder, manual control means on said tool for controlling the operation of said motor means, an automatic control valve remote from said tool operative in timed relationship with said manual control means for admitting pressurized fluid to said cylinder to withdraw the driver from the jaws and to move said nosepiece and said motor means away from each other after the fastener has been driven.

4. In a fastener inserting tool, a driver, motor means operatively connected to said driver for imparting driving motion thereto, a fastener retaining nosepiece movable relative to said motor means, a cylinder fixed to said nosepiece, a pair of yieldable jaws on said nosepiece for supporting a fastener in the path of motion of said driver,

said driver extending from said motor means through said cylinder and movable between said jaws to drive the fastener therefrom when said motor means and said nosepiece are moved toward each other, a piston on said driver and slidable within said cylinder, manual control means on said tool for controlling the operation of said motor means, an accumulator for pressurized fluid, means providing communication between said accumulator and said cylinder including an automatic control valve operative in timed relationship with said manual control means to direct pressurized fluid to said cylinder only when the manual control means is positioned to interrupt operation of said motor means.

5. In a fastener inserting tool, a driver, motor means operatively connected to said driver for imparting driving 7 motion thereto, a fastener retaining nosepiece movable relative to said motor means, a cylinder fixed to said nosepiece, a pair of yieldable jaws on said nosepiece for supporting a fastener in the path of motion of said driver, said driver extending from said motor means through said cylinder and movable between said jaws to drive the fastener therefrom when said means and said nosepiece are moved toward each other, a piston on said driver and slidable within said cylinder, manual control means on said tool for controlling the operation of said motor means, an accumulator for pressurized fluid, means providing communication between said acctunulator and said cylinder including an automatic control valve operative in timed relationship with said manual control means to direct pressurized fluid to said cylinder only when the manual control means is positioned to interrupt operation of said motor means, and means for varying the amount of pressurized fluid passing from said accumulator to said cylinder.

6. In a fastener inserting tool, a driver, motor means operatively connected to said driver for imparting driving motion thereto, a fastener retaining nosepiece movable relative to said motor means, a cylinder fixed to said nosepiece, a pair of yieldable jaws on said nosepiece for supporting a fastener in the path of motion of said driver, said driver extending from said motor means through said cylinder and movable between said jaws to drive the fastener therefrom when said motor means and said nosepiece are moved toward each other, a piston on said driver and slidable within said cylinder, manual control means for controlling the operation of said motor means, an accumulator for pressurized fluid, means providing communication between said accumulator and said cylinder including an automatic control valve operative in timed relationship with said manual control means, said automatic control valve including means for directing pressurized fluid to said accumulator when said motor means is being operated and from said accumulator to said cylinder after said motor means has ceased operating to withdraw the driver from the jaws.

References Cited in the file of this patent UNITED STATES PATENTS 207,956 Dunham Sept. 10, 1878 217,472 Messer July 15, 1879 248,668 Rochow Oct. 25, 1881 536,427 Hayes Mar. 26, 1895 1,014,639 Colwell Jan. 16, 1912 1,703,458 Ruff Feb. 26, 1929 2,416,312 Harkeem Feb. 25, 1947 2,802,451 Chellis et a1. Aug. 13, 1957 

